I am working on designing a circuit card using one of our favorite AVR controllers. One of the many functions for this controller design will be to switch 115VAC (400Hz) power to a heater circuit that will be located remotely. The 115VAC current will be fairly low (< 750 mA). I would like to get a discussion started as to opinions regarding design techniques (aka precautions) for ensuring safety for both the user and the low voltage circuitry. The plan is to use an opto-isolated solid state relay to do the switching. Obviously the 115VAC power will be fused as it comes on to the PCB. What other suggestions would our resident engineers recommend?